<html>
    <head>
        <title>Hello</title>
        <style>
            h1{
                color: #745863;
                font-size: 48px;
                text-shadow: 3px 3px 3px 3px #3da09d82;
            }
        </style>
        <script>
            function change(){
                document.getElementsByTagName('h1')[0].style.color='#ff0000';
            }
        </script>
    </head>
    <body>
        <h1 onclick="change()">hello,world!</h1>
    </body>
</html>